This core resource will furnish biostatistical consultation to all investigators participating in the research of this program project grant. The biostatistics core will assume line responsibility for all clinical studies with regard to the statistical aspects of study design, data management, analysis and reporting of study results for Projects I and II. In cases where the studies are done jointly with the City of Hope National Medical Center (COH) or the Southwest Oncology Group (SWOG) the work will be done in conjunction with corresponding staff at the other organizations. This core will also serve as a statistical and data management resource for all experimental projects (III-VIII) of this grant application. Allocation of core efforts to the projects in this program are seen roughly as follows: I (40%), II (40%), III-VIII (20%). In addition to providing support for specific projects listed in this program project grant application, our biostatistics operation has responsibility for statistical and data management support for the total bone marrow transplant (BMT) research function at Stanford University. Thus the core maintains a data base that tracks information on all patients receiving a bone marrow transplant at Stanford. (Ninety percent of BMT recipients are participants of clinical and/or experimental studies covered by this program project grant whereas 10% are patients with diseases other than leukemia or lymphoma who are not involved in research related to this application). No funds aer requested for research which is not directly related to the program project grant "Marrow Grafting for Leukemia and Lymphoma." Staff members are available to assist in querying the data base and designing and performing statistical analyses. This assures that maximum use of an important resource is made to answer research questions.